When a new kind of sports suddenly appeared, the world is enveloped in an unprecedented movement… The name of that sport is none other than "onigokko"—it's tag! Various rules have been created for the highly stragetic and competitive Japanese game, and onigokko continues to develop.
In the blink of an eye, onigokko has spread and reached the top of the world. The sport has grown to the level where it has an international competition known as "Onigokko Grand Athletics" (OGA), where the top athletes of onigokko gather and face each other.
The story begins when Ogaki Ayumu and Tendo Ran meet each other as they enroll to Kishiro High School, a prestigious private school with honorable, long-standing history in OGA. Their encounter is about to bring a new breeze into the world of onigokko…